Mining machine



June 9, 1942. R. K. JEFFREY ETAL MINING MACHINE Original Filed May 6, 1938 2 5 \Il/ O\\ 0 I, o 1 0 O O o o I: o o o 0 o O O O 0 w 0 v m 0 w s o A O 0 0 WM 0 R M 0 N flyvsuroels ROBERT K. JEFFRE C AND 1 ELL, DECEASED, 9L5 Ammmmr LEWISE.MITCH RICHARD D. Nncu Patentecl June 9, 1942 MINING MACHINE Robert K. Jeffrey, Columbus, Ohio, and Lewis E. Mitchell, deceased, late of Columbus, Ohio, by Richard D. Nichols, administrator, Columbus,

Ohio, assignors to The Jeffrey Company, a corporation of Ohio Manufacturing Original application May 6, 1938, Serial No. 206,448, now Patent No. 2,263,779, dated November 25, 1941.

Divided and this application November 4, 1940, SerialNo. 364,328

1 Claim. (01. 105 -105) This invention relates to a mining machine, and particularly to drive mechanism therefor.

An object of the invention is to provide improved drive mechanism for a mining machine.

Another object of the invention is to provide a mining machine which incorporates therein improved chain driving mechanism with simple and effective means for maintaining the chain drive mechanism at a proper tension at all times.

Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claim.

This application is a division of our application a counter-shaft 602 journaled in bearings carried by two spaced upright plates, one of which is supported from bottom plate 546 of platform Serial No. 206,448 filed May 6, 1938, for an improvement in Mining machines, now Patent No. 2,263,779, dated November 25, 1941.

In the accompanying drawing:

Fig. 1 is a diagrammatic plan view showing a mining machine incorporating the structure of our invention; and

Fig. 2 is an enlarged sectional and elevation view showing the drive mechanism comprising the structure of our invention.

In Fig. 1 of the drawing there is illustrated diagrammatically a mining machine which incorporates the features of the invention herein claimed. The mining machine is disclosed in full detail in our parent application above identified, of which this application is a divison, and so no attempt will be made to describe it in detail in its entirety, only those parts forming the subject matter of the invention herein claimed being specifically described.

Said mining machine includes a truck 45 which supports a turntable 11 upon is mounted for adjustment in a vertical plane a supplementary frame I which has a forwardly extending neck I09 carrying a turnover head mechanism I59 which provides for various adjustments of a kerf cutting mechanism I60.

Extending rearwardly from and supported by the truck 45 is a platform 545 which carries a considerable amount of mechanism some of which per se is not pertinent to the invention herein claimed.

By reference to'Figs. 1 and 2 of the drawing, it will be seen that there is illustrated diagrammatically an electric driving motor 56l mounted upon the platform 545 which motor 56l has a pinion gear 565 connected to the armature shaft which meshes with the gear 561 which is in turn connected by appropriate connecting means illustrated more completely in our parent application above identified, to a gear 598.

Gear 598 meshes with a large gear 599 keyed to 545 and the other of which is supported from a platform 564.

Loosely journaled on the counter-shaft 602 is a drive sprocket 601 driven from shaft 602 through a jaw clutch as fully disclosed in our parent application.

Below the drive sprocket 601 is a pair of guiding and tensioning' sprockets H6 and 611 mounted on shafts H8 and 6| 9, respectively, both of which are carried by a pivoted chain adjusting arm 620 pivotally mounted by pin 62l extending between a pair of spaced upright plates, one of which is seen at 622, which plates are supported from bottom plate 546, the free end of which arm 620 has cooperating therewith a chain adjusting set screw 624 which may be adjusted to swing said arm 620 about the axis of pin 621. Arm 620 is formed by a pair of spaced members between which sprockets 6H and H9 are carried.

Reeved about the sprockets 601, M6 and 6H and about a sprocket 625, keyed to the rearward axle 52 of the truck 45 is a drive chain 626, the lower run of which is supported intermediate the sprockets H6 and 625 by a bearing pad 621 and the upper run of which is supported intermediate the sprockets 6H and 625 by bearing pad 628. It is evident that by swinging the arm 620 about the pin 621 under the influence of the set screw 624 the tension of drive chain 626 may be adjusted. It is to be particularly noted that the drive chain does not extend in a straight line between the sprocket 601 and the sprocket 625 but is generally L-shaped in that both the drive and slack runs first extend downwardly from the sprocket 601 through an opening in the platform bottom plate 564, then extend generally horizontally to sprocket 625. This provides for a relatively large amount of adjustment in the length of the chain 626 so that the distance between the axle 52 and the shaft 602 need not be determined with extreme accuracy. It all provides for a relatively large take-up which may be caused by stretching of the chain 626 so that a complete link of the chain 626 may be removed without extending beyond the limits of adjustment thereof afforded by the arm 620.

It will be thus seen that we have provided simple but effective drive mechanism from the motor 561 to the rear axle of the truck 45 by which the mining machine may be propelled. The chain tensioning mechanism not only functions in this capacity but also acts as a guide to guide the general path of the chain first downwardly and then longitudinally which makes for a minimum interference thereof with other mechanism of the mining machine. This is a matter of considerable importance in a mining machine where the overall height must be maintained at a minimum, and consequently as many operating parts as possible are concentrated in the restricted space available.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by the claim hereto appended, and we therefore wish not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodiment of our invention, what we desire to secure by Letters Patent of the United States is:

In apparatus of the class described, the combination with a truck including a platform having a bottom plate, of an electric motor mounted on said platform bottom plate, wheel means for transporting said truck, a drive axle for said truck, mechanism for driving said truck axle from said motor including a sprocket driven by said motor, a sprocket keyed to said truck axle and an endless chain extending between said sprockets, both the drive and slack runs of said endless chain being generally L-shaped and extending from said motor driven sprocket downwardly through an opening in said platform bottom plate and then generally horizontally, tension and guiding means for said chain comprising an arm pivoted at a point below said motor driven sprocket and between the runs of said chain, a pair of idler sprockets on' said arm, one meshing with each run of said chain, and means supported by said platform bottom plate for swinging said pivoted arm about its pivot to adjust the tension of said chain.

ROBERT K. JEFFREY.

RICHARD D. NICHOLS, Administrator of the Estate of Lewis E. M itehell,

Deceased. 

